1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
|
/**
* @file ws2812.c
* @author Austin Glaser <austin.glaser@gmail.com>, Joerg Wangemann <joerg.wangemann@gmail.com>
* @brief WS2812 LED driver
*
* Copyright (C) 2016 Austin Glaser, 2017 Joerg Wangemann
*
* This software may be modified and distributed under the terms
* of the MIT license. See the LICENSE file for details.
*
* @todo Put in names and descriptions of variables which need to be defined to use this file
*
* @addtogroup WS2812
* @{
*/
/* --- PRIVATE DEPENDENCIES ------------------------------------------------- */
// This Driver
#include "ws2812_f4.h"
// Standard
#include <stdint.h>
// ChibiOS
#include "ch.h"
#include "hal.h"
#include "wait.h"
// Application
//#include "board.h"
// TODO: Add these #define's to the headers of your project.
// Pin, timer and dma are all connected, check them all if you change one.
// Tested with STM32F4, working at 144 or 168 MHz.
//#define WS2812_LED_N 2 // Number of LEDs
//#define PORT_WS2812 GPIOB
//#define PIN_WS2812 9
//#define WS2812_TIM_N 4 // timer, 1-11
//#define WS2812_TIM_CH 3 // timer channel, 0-3
//#define WS2812_DMA_STREAM STM32_DMA1_STREAM2 // DMA stream for TIMx_UP (look up in reference manual under DMA Channel selection)
//#define WS2812_DMA_CHANNEL 6 // DMA channel for TIMx_UP
// The WS2812 expects 5V signal level (or at least 0.7 * VDD). Sometimes it works
// with a 3V signal level, otherwise the easiest way to get the signal level to 5V
// is to add an external pullup resistor from the DI pin to 5V (10k will do) and
// configure the pin as open drain.
// (An SMD resistor is easily solders on the connections of a light strip)
// Uncomment the next line if an external pullup resistor is used.
//#define WS2812_EXTERNAL_PULLUP
/* --- CONFIGURATION CHECK -------------------------------------------------- */
#if !defined(WS2812_LED_N)
#error WS2812 LED chain length not specified
#elif WS2812_LED_N <= 0
#error WS2812 LED chain length set to invalid value
#endif
#if !defined(WS2812_TIM_N)
#error WS2812 timer not specified
#endif
#if defined(STM32F2XX) || defined(STM32F4XX) || defined(STM32F7XX)
#if WS2812_TIM_N <= 2
#define WS2812_AF 1
#elif WS2812_TIM_N <= 5
#define WS2812_AF 2
#elif WS2812_TIM_N <= 11
#define WS2812_AF 3
#endif
#elif !defined(WS2812_AF)
#error WS2812_AF timer alternate function not specified
#endif
#if !defined(WS2812_TIM_CH)
#error WS2812 timer channel not specified
#elif WS2812_TIM_CH >= 4
#error WS2812 timer channel set to invalid value
#endif
/* --- PRIVATE CONSTANTS ---------------------------------------------------- */
#define WS2812_PWM_FREQUENCY (STM32_SYSCLK/2) /**< Clock frequency of PWM, must be valid with respect to system clock! */
#define WS2812_PWM_PERIOD (WS2812_PWM_FREQUENCY/800000) /**< Clock period in ticks. 1 / 800kHz = 1.25 uS (as per datasheet) */
/**
* @brief Number of bit-periods to hold the data line low at the end of a frame
*
* The reset period for each frame must be at least 50 uS; so we add in 50 bit-times
* of zeroes at the end. (50 bits)*(1.25 uS/bit) = 62.5 uS, which gives us some
* slack in the timing requirements
*/
#define WS2812_RESET_BIT_N (50)
#define WS2812_COLOR_BIT_N (WS2812_LED_N*24) /**< Number of data bits */
#define WS2812_BIT_N (WS2812_COLOR_BIT_N + WS2812_RESET_BIT_N) /**< Total number of bits in a frame */
/**
* @brief High period for a zero, in ticks
*
* Per the datasheet:
* WS2812:
* - T0H: 200 nS to 500 nS, inclusive
* - T0L: 650 nS to 950 nS, inclusive
* WS2812B:
* - T0H: 200 nS to 500 nS, inclusive
* - T0L: 750 nS to 1050 nS, inclusive
*
* The duty cycle is calculated for a high period of 350 nS.
*/
#define WS2812_DUTYCYCLE_0 (WS2812_PWM_FREQUENCY/(1000000000/450))
/**
* @brief High period for a one, in ticks
*
* Per the datasheet:
* WS2812:
* - T1H: 550 nS to 850 nS, inclusive
* - T1L: 450 nS to 750 nS, inclusive
* WS2812B:
* - T1H: 750 nS to 1050 nS, inclusive
* - T1L: 200 nS to 500 nS, inclusive
*
* The duty cycle is calculated for a high period of 800 nS.
* This is in the middle of the specifications of the WS2812 and WS2812B.
*/
#define WS2812_DUTYCYCLE_1 (WS2812_PWM_FREQUENCY/(1000000000/900))
/* --- PRIVATE MACROS ------------------------------------------------------- */
/**
* @brief Generates a reference to a numbered PWM driver
*
* @param[in] n: The driver (timer) number
*
* @return A reference to the driver
*/
#define PWMD(n) CONCAT_EXPANDED_SYMBOLS(PWMD, n)
#define WS2812_PWMD PWMD(WS2812_TIM_N) /**< The PWM driver to use for the LED chain */
/**
* @brief Determine the index in @ref ws2812_frame_buffer "the frame buffer" of a given bit
*
* @param[in] led: The led index [0, @ref WS2812_LED_N)
* @param[in] byte: The byte number [0, 2]
* @param[in] bit: The bit number [0, 7]
*
* @return The bit index
*/
#define WS2812_BIT(led, byte, bit) (24*(led) + 8*(byte) + (7 - (bit)))
/**
* @brief Determine the index in @ref ws2812_frame_buffer "the frame buffer" of a given red bit
*
* @note The red byte is the middle byte in the color packet
*
* @param[in] led: The led index [0, @ref WS2812_LED_N)
* @param[in] bit: The bit number [0, 7]
*
* @return The bit index
*/
#define WS2812_RED_BIT(led, bit) WS2812_BIT((led), 1, (bit))
/**
* @brief Determine the index in @ref ws2812_frame_buffer "the frame buffer" of a given green bit
*
* @note The green byte is the first byte in the color packet
*
* @param[in] led: The led index [0, @ref WS2812_LED_N)
* @param[in] bit: The bit number [0, 7]
*
* @return The bit index
*/
#define WS2812_GREEN_BIT(led, bit) WS2812_BIT((led), 0, (bit))
/**
* @brief Determine the index in @ref ws2812_frame_buffer "the frame buffer" of a given blue bit
*
* @note The blue byte is the last byte in the color packet
*
* @param[in] led: The led index [0, @ref WS2812_LED_N)
* @param[in] bit: The bit index [0, 7]
*
* @return The bit index
*/
#define WS2812_BLUE_BIT(led, bit) WS2812_BIT((led), 2, (bit))
/* --- PRIVATE VARIABLES ---------------------------------------------------- */
static uint32_t ws2812_frame_buffer[WS2812_BIT_N + 1]; /**< Buffer for a frame */
/* --- PUBLIC FUNCTIONS ----------------------------------------------------- */
/*
* Gedanke: Double-buffer type transactions: double buffer transfers using two memory pointers for
the memory (while the DMA is reading/writing from/to a buffer, the application can
write/read to/from the other buffer).
*/
void ws2812_init(void)
{
// Initialize led frame buffer
uint32_t i;
for (i = 0; i < WS2812_COLOR_BIT_N; i++) ws2812_frame_buffer[i] = WS2812_DUTYCYCLE_0; // All color bits are zero duty cycle
for (i = 0; i < WS2812_RESET_BIT_N; i++) ws2812_frame_buffer[i + WS2812_COLOR_BIT_N] = 0; // All reset bits are zero
// Configure pin as AF output. If there's an external pull up resistor the signal level is brought to 5V using open drain mode.
#ifdef WS2812_EXTERNAL_PULLUP
palSetPadMode(PORT_WS2812, PIN_WS2812, PAL_MODE_ALTERNATE(WS2812_AF) | PAL_STM32_OTYPE_OPENDRAIN);
#else
palSetPadMode(PORT_WS2812, PIN_WS2812, PAL_MODE_ALTERNATE(WS2812_AF) | PAL_STM32_OTYPE_PUSHPULL); //PAL_MODE_STM32_ALTERNATE_PUSHPULL);
#endif
//palClearPad(PORT_WS2812, PIN_WS2812);
//wait_ms(1);
// PWM Configuration
#pragma GCC diagnostic ignored "-Woverride-init" // Turn off override-init warning for this struct. We use the overriding ability to set a "default" channel config
static const PWMConfig ws2812_pwm_config = {
.frequency = WS2812_PWM_FREQUENCY,
.period = WS2812_PWM_PERIOD, //Mit dieser Periode wird UDE-Event erzeugt und ein neuer Wert (Länge WS2812_BIT_N) vom DMA ins CCR geschrieben
.callback = NULL,
.channels = {
[0 ... 3] = {.mode = PWM_OUTPUT_DISABLED, .callback = NULL}, // Channels default to disabled
[WS2812_TIM_CH] = {.mode = PWM_OUTPUT_ACTIVE_HIGH, .callback = NULL}, // Turn on the channel we care about
},
.cr2 = 0,
.dier = TIM_DIER_UDE, // DMA on update event for next period
};
#pragma GCC diagnostic pop // Restore command-line warning options
// Configure DMA
//dmaInit(); // Joe added this
dmaStreamAllocate(WS2812_DMA_STREAM, 10, NULL, NULL);
dmaStreamSetPeripheral(WS2812_DMA_STREAM, &(WS2812_PWMD.tim->CCR[WS2812_TIM_CH])); // Ziel ist der An-Zeit im Cap-Comp-Register
dmaStreamSetMemory0(WS2812_DMA_STREAM, ws2812_frame_buffer);
dmaStreamSetTransactionSize(WS2812_DMA_STREAM, WS2812_BIT_N);
dmaStreamSetMode(WS2812_DMA_STREAM,
STM32_DMA_CR_CHSEL(WS2812_DMA_CHANNEL) | STM32_DMA_CR_DIR_M2P | STM32_DMA_CR_PSIZE_WORD | STM32_DMA_CR_MSIZE_WORD |
STM32_DMA_CR_MINC | STM32_DMA_CR_CIRC | STM32_DMA_CR_PL(3));
// M2P: Memory 2 Periph; PL: Priority Level
// Start DMA
dmaStreamEnable(WS2812_DMA_STREAM);
// Configure PWM
// NOTE: It's required that preload be enabled on the timer channel CCR register. This is currently enabled in the
// ChibiOS driver code, so we don't have to do anything special to the timer. If we did, we'd have to start the timer,
// disable counting, enable the channel, and then make whatever configuration changes we need.
pwmStart(&WS2812_PWMD, &ws2812_pwm_config);
pwmEnableChannel(&WS2812_PWMD, WS2812_TIM_CH, 0); // Initial period is 0; output will be low until first duty cycle is DMA'd in
}
ws2812_err_t ws2812_write_led(uint32_t led_number, uint8_t r, uint8_t g, uint8_t b)
{
// Check for valid LED
if (led_number > WS2812_LED_N) return WS2812_LED_INVALID;
// Write color to frame buffer
for (uint32_t bit = 0; bit < 8; bit++) {
ws2812_frame_buffer[WS2812_RED_BIT(led_number, bit)] = ((r >> bit) & 0x01) ? WS2812_DUTYCYCLE_1 : WS2812_DUTYCYCLE_0;
ws2812_frame_buffer[WS2812_GREEN_BIT(led_number, bit)] = ((g >> bit) & 0x01) ? WS2812_DUTYCYCLE_1 : WS2812_DUTYCYCLE_0;
ws2812_frame_buffer[WS2812_BLUE_BIT(led_number, bit)] = ((b >> bit) & 0x01) ? WS2812_DUTYCYCLE_1 : WS2812_DUTYCYCLE_0;
}
// Success
return WS2812_SUCCESS;
}
void ws2812_setleds(LED_TYPE *ledarray, uint16_t number_of_leds)
{
for(int i = 0; i < number_of_leds; i++) {
ws2812_write_led(i, ledarray[i].r, ledarray[i].g, ledarray[i].b);
}
}
/** @} addtogroup WS2812 */
|
